The report published following the inquest called on KCAS to take action to prevent future deaths.
According to the report, Emily's friends said she had possibly taken MDMA not long before she entered the festival, but she was also seen taking a tablet shortly after getting there.
She was taken to a medical tent at the event at around 15:20 BST and left the site in an ambulance an hour later.
The teenager arrived at Queen Elizabeth The Queen Mother Hospital around five minutes later, where she suffered a cardiac arrest and was pronounced dead shortly after 18:00.
Catherine Wood, assistant coroner for north-east Kent, said training of the KCAS staff involved was "minimal" and they had "little experience or training in relation to management of patients having taken drugs".
"More training should have been provided to assist the staff in how to safely manage those under the influence of illicit substances," the coroner added.
Ms Wood also raised concerns that the ambulance was not as equipped as an NHS vehicle would have been.
The coroner further criticised the fact that the hospital was not called ahead of the crew arriving there with Emily.
"There was a lack of clarity regarding who had responsibility for making a pre-alert call to the hospital and given this young girl was significantly unwell this should have been done," Ms Wood added.
"This, in part, may have been due to the lack of recognition of the seriousness of her symptoms and, therefore, potentially linked with training of staff.
A KCAS spokesperson said: "As a healthcare provider, we are committed to continuous learning, service improvement and ensuring the highest standards of patient safety, comfort and care."
Crews sent to cover such events will now receive training covering recognition of drug and alcohol intoxication, according to the service.
KCAS added that on-site paramedics directed on the day of the incident that a pre-alert call to the hospital was not needed, but internal protocols have now been clarified to say "crews are now explicitly empowered to pre-alert independently if in doubt".
